When using a multiboot capable bootloader this is exactly the field which
should be used.
Replace the deprecation wording with a reference to the information on the
priority of the bootargs fields.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Julien Grall <julien.grall@linaro.org>
It is the compatible string which matters, not the absolute path, and in any
case /chosen/module@N is more often used than /chosen/modules/module@N.
Reported-by: Fu Wei <fu.wei@linaro.org>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Julien Grall <julien.gral@linaro.org>
The chosen node's bootargs property should be used for Xen if there is a dom0
kernel multiboot module with a command line, not just if xen,dom0-bootargs is
present.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Julien Grall <julien.linaro.org>
Currently we use the chosen/bootargs property as the Xen commandline
and rely on xen,dom0-bootargs for Dom0. However this brings issues
with bootloaders, which usually build bootargs by bootscripts for a
Linux kernel - and not for the entirely different Xen hypervisor.
Introduce a new possible device tree property "xen,xen-bootargs"
explicitly for the Xen hypervisor and make the selection of which to
use more fine grained:
- If xen,xen-bootargs is present, it will be used for Xen.
- If xen,dom0-bootargs is present, it will be used for Dom0.
- If xen,xen-bootargs is _not_ present, but xen,dom0-bootargs is,
bootargs will be used for Xen. Like the current situation.
- If no Xen specific properties are present, bootargs is for Dom0.
- If xen,xen-bootargs is present, but xen,dom0-bootargs is missing,
bootargs will be used for Dom0.
The aim is to allow common bootscripts to boot both Xen and native
Linux with the same device tree blob. If needed, one could hard-code
the Xen commandline into the DTB, leaving bootargs for Dom0 to be set
by the (non Xen-aware) bootloader.
I will send out a appropriate u-boot patch, which writes the content
of the "xen_bootargs" environment variable into the xen,xen-bootargs
dtb property.
Signed-off-by: Andre Przywara <andre.przywara@linaro.org>
Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Both OMAP5 and sun6i/sun7i SoCs share this UART driver for early_printk.
Signed-off-by: Chen Baozi <baozich@gmail.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
With the help of the previous patches add a stanza to
xen/arch/arm/Rules.mk to specify the UART configuration of the
Calxeda Midway machine.
The information has been taken from the Linux kernel's .dts file.
This can be enabled by adding "CONFIG_EARLY_PRINTK=midway" to
Config.mk.
Signed-off-by: Andre Przywara <andre.przywara@calxeda.com>
Reviewed-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Though the ARM Fastmodel software emulator mimics a Versatile Express
board, the boot process is different compared to the real hardware,
so the early printk differs slightly. Create a new early-printk
target to model this correctly.
Signed-off-by: Andre Przywara <andre.przywara@calxeda.com>
Reviewed-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
The UART memory mapped base address is currently hardcoded in the
early-printk UART driver, which denies the driver to be used by
two machines with a different mapping.
Move this definition out to xen/arch/arm/Rules.mk, allowing easier
user access and later sharing of the driver.
Signed-off-by: Andre Przywara <andre.przywara@calxeda.com>
Reviewed-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
While it seems obvious to initialize the UART before using it, chances
are that some firmware code or the bootloader already did this.
So it may actually be a good idea to skip the initialization, in fact
this fixes early printk on my TC2 Versatile Express.
So provide an option in xen/arch/arm/Rules.mk to only initialize the
UART when needed.
Signed-off-by: Andre Przywara <andre.przywara@calxeda.com>
Reviewed-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
For early-printk the used baud rate was hardcoded in the code, using
precalculated divisor values.
Let the calculation of these values be done by the preprocessor and
use a human readable value in xen/arch/arm/Rules.mk to drive this.
Signed-off-by: Andre Przywara <andre.przywara@calxeda.com>
Reviewed-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Add CONFIG_EARLY_PRINTK options in configs/arm{32,64}.mk to let the user
to choose if he wants to have early output, ie before the console is initialized.
This code is specific for each UART. When CONFIG_EARLY_PRINTK is enabled,
Xen will only be able to run on a board with this UART.
If a developper wants to add support for a new UART, he must implement the
following assembly macro/define:
- EALY_UART_BASE_ADDRESS: variable which contains the physical base address
for the UART
- early_uart_init: initialize the UART
- early_uart_ready: check and wait until the UART can transmit a new
character
- early_uart_transmit: transmit a character
For more details about the parameters of each function,
see arm{32,64}/debug-pl011.inc comments.
Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
The bootloader should populate /chosen/modules/module@<N>/ for each
module it wishes to pass to the hypervisor. The content of these nodes
is described in docs/misc/arm/device-tree/booting.txt
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Suravee Suthikulpanit
Frediano Ziglio
Jon Fraser
Ian Campbell
Julien Grall
Andre Przywara
Chen Baozi
Andre Przywara
Anthony PERARD